Most microprocessors and microcontrollers have bi-directional external reset pins. Bi-directional reset pins act as both an input and an output. When used as an input, driving (forcing) the reset pin to a logic one or logic zero forces the processor to restart or reset. When used as an output, the signal or state of the reset pin provides an indication as to why an event or condition occurred which caused the processor to reset itself.
A processor can reset itself for a variety of reasons. Such reasons include but are not limited to the expiration of a hardware “watchdog timer,” a clock pulse frequency monitor, a voltage range monitor and a memory protection unit. Signals that are output on a processor reset pin can thus be evaluated with specialized equipment, i.e., “debug” tools, to determine why a processor reset. Unfortunately, tools that are capable of reading signals on reset pin are costly and cumbersome to operate. A cost efficient and real time evaluation of a reset pin output signal is thus problematic. An apparatus for, and a method of evaluating signals on a reset pin would be an improvement over the prior art.